A general acoustic device includes a magnetic circuit system and a vibration system, the vibration system includes a voice coil and a vibrating diaphragm that are connected to each other, and the electrified voice coil drives the vibrating diaphragm to vibrate under the action of the magnetic circuit system so as to produce a sound.
A terminal of a flexible printed circuit board (FPC board) is in communication with the voice coil after being welded to the voice coil by using a spot welding process so as to supply power to the voice coil.
The vibrating diaphragm serving as a core part of the acoustic device such as a speaker has great influence on performance of the acoustic device. The vibrating diaphragm in the related art is a dome-type vibrating diaphragm, and the dome is made of an aluminum foil material. In a mass production process of acoustic devices 10, the phenomenon that the FPC board is broken down at a welding point position may occur when the spot welding temperature and pressure are overhigh during spot welding of the FPC board and the voice coil. The dome is arranged above the welding point position of the spot welding. Consequently, the FPC board may break down the aluminum foil dome, resulting in a short circuit, which makes the voice coil and the aluminum foil dome conducted, causing scrap of the acoustic device.
If an insulating material is selected as a dome material to avoid a short circuit of the dome, the strength and weight of the dome will be affected, and furthermore, the performance of the dome is affected.